Method for grinding of cam profiles

Abstract

The present invention relates to a method for grinding of cam profiles on a camshaft ( 1 ), having an inner shaft ( 5 ) and an outer shaft ( 4 ) arranged coaxially one inside the other and mounted to rotate with respect to one another. The camshaft ( 1 ) additionally has first and second cams ( 2, 3 ) that can rotate with respect to one another over a limited circumferential angle about the camshaft axis ( 6 ), the first cams ( 2 ) of which are fixedly connected to the inner shaft ( 5 ) and the second cams ( 3 ) of which are fixedly connected to the outer shaft ( 4 ). It is essential to this invention that during and/or after the grinding operation a fluid is forced under pressure into the outer shaft ( 4 ), thereby preventing penetration of grinding dust into the interspace ( 8 ) between the first cams ( 2 ) and the outer shaft ( 4 ) or flushing out any grinding dust that has already penetrated.

1. A method for grinding of cam profiles on a camshaft ( 1 ), which camshaft ( 1 )
 has an inner shaft ( 5 ) and an outer shaft ( 4 ) arranged coaxially one inside the other and mounted with respect to one another, 
 has first cams ( 2 ) and second cams ( 3 ) that can rotate with respect to one another about the camshaft axis ( 6 ) over a limited circumferential angle, the first cams ( 2 ) being fixedly connected to the inner shaft ( 5 ) and the second cams ( 3 ) being fixedly connected to the outer shaft ( 4 ), 
 
     wherein during the grinding process and/or thereafter, the method includes: forcing fluid under pressure into the outer shaft ( 4 ), thereby forcing fluid into a ring space ( 15 ) between the inner shaft ( 5 ) and outer shaft ( 4 ), wherein the fluid flows through a longitudinal hole ( 13 ) and into a ring gap ( 8 ) between the first cam ( 2 ) and the outer shaft ( 4 ) thereby preventing grinding dust from penetrating into the ring gap ( 8 ) or flushing out any grinding dust that has already penetrated into the ring gap ( 8 ). 
   
   
     2. The method according to  claim 1 , wherein the pressure of the fluid during the grinding process is selected to be so high that the outer shaft ( 4 ) undergoes elastic deformation and ring gaps ( 8 ) between the first cams ( 2 ) and the outer shaft ( 4 ) are at least reduced in size. 
   
   
     3. The method according to  claim 2 , wherein the pressure of the fluid during the grinding process is selected to be so high that the outer shaft ( 4 ) undergoes elastic deformation and the first cams ( 2 ) are in close contact with an outer lateral surface of the outer shaft ( 4 ). 
   
   
     4. The method according to  claim 1 , wherein a hydraulic medium is used as the fluid. 
   
   
     5. The method according to  claim 4 , wherein purified oil is used as the hydraulic medium. 
   
   
     6. The method according to  claim 1 , wherein a gas is used as the fluid. 
   
   
     7. The method according to  claim 6 , wherein (compressed) air is used as the gas.